WIPI1 (WD repeat domain, phosphoinositide interacting-1), also known as WIPI1, ATG18 or WIPI49, is thought to play a role in autophagy and may regulate protein trafficking in certain recycling pathways. It contains three WD repeats and has a 7-bladed propeller structure with a conserved motif that facilitates its interaction with other proteins. WIPI1 localizes to cytoplasmic vesicles, endosomes, clathrin-coated vesicles and the trans-Golgi network. It is ubiquitously expressed with highest expression in heart, testis, placenta, pancreas and skeletal muscle. WIPI1 is upregulated in a variety of tumors, suggesting a role in carcinogenesis.Synonyms: Atg18 protein homolog, WD repeat domain phosphoinositide-interacting protein 1, WD40 repeat protein interacting with phosphoinositides of 49 kDa, WIPI1, WIPI49